Description of problem:

pciAddress of SR-IOV NICs defined in the VM is not respected, in the generated libvirt XML and therefore inside the Guest the NIC properties are randomly mixed.

For example, see these 4 SR-IOV NICs defined:

• macAddress: 02:9f:a6:00:01:40
  model: virtio
  name: nic-1
  pciAddress: "0000:20:00.0"
  sriov: {}
• macAddress: 02:9f:a6:00:01:41
  model: virtio
  name: nic-2
  pciAddress: "0000:21:00.0"
  sriov: {}
• macAddress: 02:9f:a6:00:01:42
  model: virtio
  name: nic-3
  pciAddress: "0000:22:00.0"
  sriov: {}
• macAddress: 02:9f:a6:00:01:43
  model: virtio
  name: nic-4
  pciAddress: "0000:23:00.0"
  sriov: {}

But inside the Guest 20:00.0 and 22:00.0 are swapped:

bus info: pci@0000:20:00.0
serial: 02:9f:a6:00:01:42

bus info: pci@0000:21:00.0
serial: 02:9f:a6:00:01:41

bus info: pci@0000:22:00.0
serial: 02:9f:a6:00:01:40

bus info: pci@0000:23:00.0
serial: 02:9f:a6:00:01:43

Version-Release number of selected component (if applicable):
4.8.4

How reproducible:
100%

Steps to Reproduce:
1. Create VM with many SR-IOV NIC with pciAddress and macAddress defined
2. Look inside the Guest, they are often mixed up.